Introduction: Coppicing woodlands is a method by which trees such as hazel and ash are cut back to almost ground level, leaving just the stumps or ‘stools’, from which many new shoots will grow from. The wood cut from these trees was once used for a wide variety of things, including thatching spars and firewood. As the trees were cut back, this allowed a lot more light to reach the woodland floor, allowing a greater diversity of both plant and animal life-forms to exist.
After eight years, once the trees have many shoots which have grown back to replace those cut off, these are then cut off too between November and March, allowing even more shoots to grow in their place, and again allowing more light to the floor. This cycle continues, however, most coppices are now neglected and have consequently over-grown.
Variables: Light- different amounts of light could cause a different variety of plants to grow in the separate coppices, as they will all photosynthesise at different rates. Also, a different light intensity could create different numbers of plants in the coppices, as well as causing them to be spread out over a wider area, creating more competition and causing some species to receive less light than they need for photosynthesis and won’t survive.
Temperature- Different temperatures may provide optimum conditions for different plant species, and so they will have greater abundance and will be more concentrated than other plant species.
Soil Temperature- different temperatures in the two coppices could encourage different species of plants to grow and thrive, and cause others to die out.
Soil Moisture- if there isn’t enough moisture in the soil, only certain plant species will survive as they have adapted to photosynthesise in those conditions. Also, lower soil moisture will prevent large numbers of a plant species from thriving in that area.
Soil pH- Whether the soil is alkaline or acidic and the extent to which they are can greatly affect the plant species which are able to grow there. If the soil is too acidic, many plants will not be able to survive, only those which have adapted to cope thriving due to the lack of inter-specific competition. Similarly, if the soil is too alkaline, only those that have adapted to those conditions will survive and thrive.
Type of Soil- soil types may greatly affect the chances of a plant species surviving and even striving, as different amounts of moisture will be held in it, with different types and amounts of nutrients. This can cause only species adapted to cope with these conditions to survive and thrive if there isn’t much competition, and others to die out due to the conditions and competition.
Soil Organic Matter- this was important as it showed the amount of available nutrients for the plants on the ground floor. The more organic matter or ‘humus’ present on the ground, the more nutrients available for the plants to use to grow, both individually and in abundance. It would also affect how concentrated the plants were.
Topography- the way that the land lies is quite important as it will determine which way the rain will run off, and in turn the abundance and the distribution of plant species within the area.
These factors were all checked to try and determine which factor was the most important. The two coppices were very near to each other, in order to try and keep the edaphic factors, temperature and the topography of the areas the same, concentrating on light as the key variable.
Hypothesis- I predict that there will be a greater abundance of plant species in the new coppice, due to the fact that there is more light present which will be used for photosynthesis, allowing many different species to grow. In the old coppice, I believe there will be less plant species, as only a few species will be able to photosynthesise in the darker conditions, as they will have adapted to those conditions.
Plan- I have already studied ecology at school, and in preparation for this investigation, we carried out an experiment on the school field, examining the distribution of broad-leaved plants in two differently managed areas. The sampling techniques used when carrying out this experiment were modified and improved for the investigation in Nower Wood, in order to achieve more accurate results.
In carrying out the investigation, a sample count was taken instead of a total count. This was because even though it isn’t as accurate, a total count would’ve taken too long. Therefore, to ensure the sample count taken was as representative as possible, we decided to take as many random samples, doing all the experiments at each quadrat, as we could, and then find their overall average.
Methods- First, a grid was created on each of the coppices. Random values were taken, which were then used to create a grid reference from where readings would be taken. At each grid reference, a group would lay a quadrat down, and the percentage cover of each different plant species present was noted, as well as the light cover and the percentage of organic matter present. At each quadrat, soil pH measurement and soil types were determined with the use of an auger, and the results were recorded. The soil temperature was also measure at each grid reference. Each group repeated this experiment five times at random grid references, and the results were combined to find an average for the entire coppice. This was then repeated in the other coppice.
Samples of the soil from each area were taken. These samples were taken back to a laboratory where the water content of the soil (soil moisture) was established and the results were recorded.